Solve 10x − 9 = −49

The solution of 10x − 9 = −49 is x = -4.

10x - 9 = -49\ \Rightarrow\ x = -4

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The lines y = 10x − 9 and y = -49 meet at x = -4. The solution of the equation is the x-coordinate of the point where the two sides are equal.

How to work it out

1
The goal is to get x alone. Undo the operations in the opposite order: first the subtraction, then the multiplication.
$10x - 9 = -49$
2
Add 9 to both sides:
$10x - 9 + 9 = -49 + 9 \ \Rightarrow\ 10x = -40$
3
Divide both sides by 10:
$\frac{10x}{10} = \frac{-40}{10} \ \Rightarrow\ x = -4$
4
Check: put x = -4 back into the equation.
$10\cdot(-4) - 9 = -40 - 9 = -49 \checkmark$

LaTeX source of the formulas on this page

\[ 10x - 9 = -49\ \Rightarrow\ x = -4 \]
\[ 10x - 9 = -49 \]
\[ 10x - 9 + 9 = -49 + 9 \ \Rightarrow\ 10x = -40 \]
\[ \frac{10x}{10} = \frac{-40}{10} \ \Rightarrow\ x = -4 \]
\[ 10\cdot(-4) - 9 = -40 - 9 = -49 \checkmark \]

Trying values of x in 10x − 9 = −49

x	10x − 9	Equals -49?
-6	-69	no
-5	-59	no
-4	-49	yes
-3	-39	no
-2	-29	no

Questions

What is x in 10x − 9 = −49?

The solution of 10x − 9 = −49 is x = -4.

How do you solve 10x − 9 = −49?

Add 9 to both sides to get 10x = -40, then divide both sides by 10 to get x = -4.

How do I check the answer?

Replace x by -4: 10(-4) − 9 = -49, which is -49.

Solve 10x − 9 = −49

How to work it out

Trying values of x in 10x − 9 = −49

Questions

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